Teacher: In this task, you are given a context and four options. Each option is a suggested ending for the context. You should read the context and pick the best ending for the context. Please answer with "A", "B", "C", and "D". 
Teacher: Now, understand the problem? If you are still confused, see the following example:
[header] How to create a christmas tree forest [title] Consider the type of tree you want to plant. [step] There are a wide variety of christmas trees and include fir, pine, spruce, cypress, and cedar. These trees thrive in different climates and look different from one another. <sep> (A) It is important to research the tree before setting up your tree to try it out to make sure you can write the tree's growing season so that you can get the most supplies you need. If you're just interested in having a tree stand out, then make sure to check for the following : [substeps] Spruce trees. (B) [substeps] Trees green may be used in a mix of green and evergreen. Greens, such as pintos and olive oil, may be more delicate than these. (C) Where the trees grow together is up to you. [substeps] Spruce trees light up the night for hours in the morning and drown out the morning sunrise between afternoons. (D) Think about where your tree forest will be located and choose a tree that can thrive in that climate. [substeps] Balsam firs are a popular christmas tree species that grow in the northern united states and canada, in hardiness zones 3-5 or states like minnesota, north dakota, and montana.
Solution: D
Reason: This is a good example. Only option D is about Christmas trees. So, it's the correct option.

Now, solve this instance: [header] How to use a graphic flight computer to find ground speed and true heading [title] Align the wind direction under the " true index " mark by rotating the azimuth plate. [step] If the winds are from 330 ° at 20 knots, align 330 under the true index. [title] Align the grid so the center grommet is over one of the heavy lines. <sep> (A) [step] Only if you are flying with the reverse rotor or with the stick, the grid should be perpendicular to the ground. [title] Align the grid so it is above one of the strong lines, connected to the main mast. (B) [step] It doesn't matter which line is used at this point. [title] Mark the wind speed by counting up from the center grommet. (C) [step] The grid turns when the wind is consistently southeast away from the ground. [title] Position a heavy line going in the direction of the ground. (D) [step] If the wind is coming from east then do not align the grid. [title] Locate the " left terminal " mark on the ground and press it with the tire iron (that is, a large metal tube that sticks out from the ground).
Student:
B